Process for concentrating nonmetallic minerals



y 22, 1952 I l. LE BARON 2,604,208

PROCESS FOR CONCENTRATING NONMETALLIC MINERALS I Filed Sept. 14. 1948/R.A M. LE 5,410.0

INVENTQR.

Patented July 22, 1952 PROCESS FOR CONCENTRATING NONMETALLIC MINERALSIra M. Le Baron, Lakeland, Fla., assignor to In: ternationai Minerals &Chemical Corporation, a corporation of New York Application September14, 1948, Serial No. 49,192

17 Claims. 1

The present invention relates to an improved process for theconcentration of non-metallic minerals from ore containing the same.'More particularly, the invention relates to an improved process in thetable concentration of nonemetallic ores such as phosphate rock,sylvinite, and the like.

The art of concentrating non-metallic min.- erals by both tabling andflotation operations is quite comprehensive and of longstanding. By suchprocesses a mineral, .in a suitably .comminuted state, may be subjectedto the action of a rifiled table by flowing an aqueous suspension orpulp of the mineral across the surface of said table in -a Stream ofwater or brine. The separation of the desired mineral values from theless desirable values or gangue is accomplished due to the inherentspecific gravity of the particular minerals present in theore. Themineral constituents having a lower specific gravity tend to fioat onthe surface of the liquid phase of the suspended ore orpulp. Byinclining the surface of the table and flowing the'suspended or pulpedore across a'riffled surface, the

lighter particles tend to flow across the ri-illes and are collectedin-a suitable launder. The particles of greater density collect alongthe leading or feed side of the rifiles, thereby achieving a separationof desired'minerals from the gangue particles "present in theore. 'Thepercent recovcry or the extent of uD-grading of any particular ore willdepend upon'the'difference' in'density between the various oreconstituents, upon the rate of flow across the riffled table, uponthedirection o'f-the riffling, upon the extent to which the surface ofthe table is inclined, and other factors. In many instances itisdesirable to preliminarily reagentize the aqueous mineral suspensionor pulped ore prior to thetabling operation. For example, it is commonknowledge-that suitably comminuted phosphate rock or sylvinite ore maybe pulped in an appropriate aqueous medium to which has been'addedreagent which willfioa-t one component of said ores while the othercomponent will tend to sink when subjected to concentration operations.The pulp may then be subjected to a tabling operation whereby'thereagentized ore is flowed in a stream of water over a rifiled, inclinedsurface. The reagentized particles are collected at thelower edge ofthetable in a-launder while the "heavier particles collect at the leadingedge of the rifiles. In-most-instances, a shaking tableis employed inorder to continuously remove the'heavier particles from-the riflies,this being accomplished'by 2 the forces imparted to the particles by theshaking action of the table. This will produce a band of heavierparticles along the side of the table opposite to the side to which theshaking force is imparted. Such a process is described in Patent No.1,968,008 issued to Chapman and Little ford, and Patent No. 2,120,535issued to Wilkinson. According to the teachings of Chapman andLittleford, the finely divided phosphatebearing material may bereagentized in an aqueous pulp with a suitable amount of a fatty acid orsimilar reagent and a suitable amount of a non-saponifiable oil. Thereagentized pulp is r then flowed in a stream of water across a rifiledshaking table, thereby achieving the concentration of the phosphatevalues in the phosphate rock to the extent that the ultimate productwhich is collected in the concentrate launder has a B.P.L. (bonephosphate of lime) content of about In a similar manner, it is knownthat sylvinite ore may be pulped in an aqueous solution which issubstantially saturated with respect to said ore, followed byreagentizing the resultant mixture with a fatty amine type re agent orwater-soluble acid addition salts thereof. The reagentized pulp is thenflowed in a stream of brine across a rifiied shaking table, therebyachieving a concentration of thesylvite (potassium chloride) valuescontained in the ore. The halite particles collect along theleadingedge-of the riffles and are removed as tailings in a band alongthe side of the table opposite to theside to which the shaking. force isime parted. Ithas also been proposed to employ this type of operationfor the up-grading .or concentration of a middling fraction from avrougher table concentration of either .phosphaterock or sylvinite ore,whereby the desired mineral values contained in such a fraction arefurther recov ered in order to improve the vover-all utility'oi theprocess. Because of characteristics inherent inythe table concentrationof minerals by fiota tion .methods, .it has been found necessary inseveral instances to employ a rougher concentration whereby aconcentrate, middling fraction, and atailings fraction are obtained.This is followedbyreprocessing the middling fraction on a cleaner table.Due to the fact that the specific gravity of the particular mineralconstituents in an credo not differ sufiiciently, a portion of thedesired'rninerals which are being floated in any table operation'vvill'ultimately be found in the, middling fraction. This is due eitherto occlusion or to mechanical entrapment ofthe -floata-bleconstituents-by "the heavier paiticles. The middling fraction is usuallydereagentized by a suitable chemical treatment; followed by a subsequenttable concentration of said fraction, in order to improve the over-allrecovery of the desired mineral constituents of the ore. Even when sucha series of tabling operations is conducted, the tailings or discardedfractionof the ore nevertheless contains a small amount of the desiredmineral constituents of the ore; but economic considerations preclude afurther recovery of suchminerals from said fraction.

It is an object of the invention to provide an improved process for thetable concentration of non-metallic minerals from ore containing thesame, by flotation methods.

It is a further object of the invention to provide an improved processfor the table concentration of non-metallic minerals from ore containingthe same, by flotation methods whereby an improvement in the over-allrecovery of particular mineral constituents present in said ore isachieved.

It is a further object of the invention to provide an improved processfor the table concentration of non-metallic minerals from ore containingthe same, by flotation methods whereby a mineral constituent, present inminor amounts in any particular flotation feed, is recovered in goodyields.

' It is a further object of the invention to provide an improved processfor the table concentration of the phosphate'values present inphosphatic ore, byfiotation methods whereby an improvement in theover-all recovery of said values is achieved. 'It is a further object ofthe invention to provide an improved process for the table concentrationofthe phosphatic'ore, by flotation methods whereby a middlings fractionobtained in a rougher table concentration of phosphate ore, and whichcontains a major amount of silica and a minor amount of phosphatevalues, may be so treated as'to achieve an improved recovery of thephosphate values contained therein.

It is a further object of the invention to provide an improved processin the tableconcentration ofsylvinite ore, by flotation methods wherebyimprovement in the over-all recovery ofeither sylvite or haliteparticles present therein is achieved.

I It is a still .further object of the invention to provide an improvedprocessfor the table concentration of a composition comprising sylviteand halite particles, by flotation methods wherebyimp'roved'concentrations of the minor constituent of said salts presentin the composition may be obtained.

The above objects, as 'well as others which will become apparent upon acomplete understanding of the invention as hereinafter fully described,are accomplished by flowing a reagentized pulp of non-metallicmineral-containing ore, which also contains'gangue particles, in astream of water, brine, or other suitable aqueous meidum over a rifiledsurface while directing a stream of Water, brine, or other suitableaqueous medium into the heavier or non-floatable and non-floatingparticles which are present and collect along the feed side of theriflies; said stream being so positioned that at least one rifiie withsaid stream precedes at least one rifiie without said stream withrespect to-the direction of flow of the feed across the rlfiied surface;The rifiied surface employed as a concentrating device, and the type ofconcentrating process employed, may be similar to those described inthe-aforesaid Chapman et al. and

Wilkinson patents; or as described in Section 11, pages 59-60 of apublication by W. A. Taggart, entitled Handbook of Mineral Dressing,published in 1945. While it is not essential to the operation of theinstant process that the riiiled surface be placed on an inclined planeduring the concentration operation, it has been found to be thepreferable practice to incline the plane of the rifiled surface so thatthe feed side of said surface is higher than the concentrate side. For

example, it has been found that the feed side of the riiiled surface maybe advantageously elevated as much as 6-12% with respect to theelevation of the concentrate side of said surface. Furthermore, while itis not essential that the rifiied surface employed as a concentratingdevice in the instant process be subjected to agitative and/orlongitudinal motion, it is the preferable practice to employ variousdevices, which are usually placed at one of the short ends of the tablesurface, in order to impart a shaking or agitative motion to saidsurface. Such devices are described in the aforesaid Taggartpublication. While the instant process will be described in terms of aninclined, riffled surface which is subjected to longitudinal agitationby means of a shaking device, it is to be understood that other types ofrifiied surfaces which may or may not be inclined, or of the shakingtype, are deemed to be within the scope of the present invention.

Generally speaking, the instant process is carried out by preparing anaqueous pulp of a nonmetallio mineral of the type which will behereinafter'described, and reagentizing said pulp with either a cationicor positive-ion agent for the flotation of non-metallic minerals havingan affinity for such agents, or employing an anionic or negative-ionagent in the event that mineral constituents having an afiinity for suchreagents are to be recovered from ores containing the same. It is knownto those skilled in the art that usually only about 1%, or a fractionthereof, of such agents will be required for the conditioning of anyparticular non-metallic mineral-containing pulp. In some instances it isdesirable to incorporate into the pulped ore a similar amount of anonsaponifiable oily material which will act as a frothing orco-operating agent and which will assist the reagent in the flotationoperation. The reagentized pulp is then subjected to the concentratingaction of an inclined, riflied surface of the type previously describedby admitting the same through a feed box placed at the upper end of saidsurface and distributing the pulp through a suitable device along theupper side of said surface. As the pulp flows across the riffled surfacedue mainly to gravitational force, it is aided by a washing stream ofwater or brine (as the case may be) Which is projected across the rifliesurface from the upper end or feed side of the table. Meanwhile, theentire table issubjected to longitudinal agitation by means of aconventional device of the type herein previously described. Thereagentized constituents of the ore proceed across the rifiies,presumably due to skin flotation, usually in a direction transvere withrespect to the movement of the table, and are ultimately collected in alaunder or similar device placed at the lower edge of the table. Thenon-floating and unreagentized, non-floatable or gangue constituents ofthe ore collect along the feed side of the rifiles, the greater portionthereof, being concentrated along the riffles at the high side of thetable. These particles are removed from the table due to the rectilinearmotion imparted thereto by the agitative'forces of the table, and arecollected a launder or other suitable device placed at the edge of the.table opposite the edge to which the shaking forces are being directed.It has now been 'found possible to increase the capacity of tablingdevices and improve the over-all recovery of any particular mineralconstituent of an ore by projecting a stream of water, brine, or othersuitable aqueous medium-preferably in the form of .jets.into thenon-floating land .non-floatable particles which .are present along the.feed side of any particular riille. The reage'ntized or floatableparticles which are usually occluded or mechanically entrapped therein,.due DO-"13116 inherent characteristics of table concentration, may beire-.- moved thereby from their mixture-with said nonfloatable particlesand collected in the. launder. at the concentrate edge of the table. Thestreams of .liquid media which are. jetted into the particlesheld'behind the riffles cause'a turbulence of said particles, therebyfreeing the reagentized and floatable minerals contained therein. Sincethis turbulence also causes some of the gan'gueparticles to flow acrossthe riille along which it has collected, it is essential to theoperation of the instant process that at least one riflle which is notequipped with aqueousstreams orjets :be .placed on the low side of theriflie which is equipped'with said streams or jets in order that saidheavier particles which flow over the riiile equipped'with awater streamor jets will not ultimately be col-' lected in the aforesaidlaundertogether with float: able particles. While it is preferable-to employ aconstruction wherein one rifile'without a jetted stream is interposedbetween riffies equipped with said streams, the apparatus may be soconstructed that a plurality of rifiles without said jetted streams maybe positioned between two 'riflles which are equipped with same.

While the instant process is applicable to the table concentration byflotation methods Whereby the desired mineral constituent of said ore isrecovered in the concentrate launder,. it is particularly adaptable to atabling operation whereby 'a middlings fraction obtained in the rougherconcentration of a non-metallic mineral ore, in accordance withprocedures described in'the'a'foresaid Chapman et a1. and Wilkinsonpatents, may be treated in order to recover the minor butdesired'm'ineral constituent ofsaid middlings fraction, while rejectingthe major undesired metallic constituents thereof as tailings. I

The term non-metallic minerals, as emp'loyed'herein and in the appendedclaims, includes all minerals which are adaptable to the concentrationof certain mineral constituents contained therein by .the flotationconcentration of a reagentized pulp containing said minerals. Suchminerals include phosphate rock'of the type found in the-phosphate areasin Florida and Tennessee; sylvinite ore such as that found in'thePermian Basin, particularly in the Carlsbad, New Mexico area; andbauxite, iron oxide, barytes, lead and zinc carbonates, and

similar ores which are amenable to flotation concentration operations.Certain of these minerals--for example, phosphate ore-may beconcentrated with negative-ion or "anionic 'reagents-such as the highmolecular weight fatty acids (oleic, palmitic, stearic and others),resin acids, rosin, talloil, napthenic acids, and the-al- I kali inetal's'oaps of such materialsfor example,

the sodiumsoap of tall oil. Also included in. the

term negative-ion agent are reagents-suchas the-case of "sylvinite ore,anionic reagents'will float the halite particles while cationic reagentswill float the sylvite particles. The instant novel process is adaptableto the table concen .tration, by flotation methods, of either sylvit'eor halite from sylvinite ore.

The instant process will be more fully understood when consideredtogether with the a'ccome panying drawing which discloses, in-Figurel, amore or less diagrammatic plan .view .of a rifiled shaking tabledeviceof thetype-manufactured by the Deister Concentrator Company. Figure 2 isan end, sectional elevation along the line A-J-A' of Figure 1; andFigure 31s a longitudinal sectional elevation along the line B--B ofFigure l. The deck of the table is 'rhombo'hee dral in shape with arectilinear imotion imparted to the table by means of any suitableshaking device such as an Overstrom head motion de vice of the typedescribed in the C. P. Taggarlt publication hereinbefore referred to,Section 11, page 76. "The agitative motion imparted to the table by thisdevice is in the direction :of the short diagonal of the table. Thetableis'tilted from the horizontal plane to allow feed .to'ilow bygravity from the feed box to the launders. Referring now to Figure 1,rifiles 2 and 13 :are places in the direction of the short diagonal andsubstantially parallel to the rectilinear motion of the table. Theriffling of the "table is accomplished by placing upon the surfacethereof,- about one inch apart, cleats 2, made of wood or othersuitablematerial. The height of the cleats will vary "from about t; inch atthehead of thetable, and feathering at the tailings-end of the table.The small riffles 2 are placed'in units of seven or eight, and betweeneach unit .is placed a rifiie 3 which is slightly higher than .thegrouped rifiles, but which also tapersor feathers towards the tailingsend of the table. 'A 11011-1 metallic mineral which has been conditionedwith reagent in an aqueous pulp is fed to the table through a feed box4, and distributed across the upper surface of the table bythe-distributing box 5. Due to the inclined plane of the table, thereagentized pulp flows across the surface thereof; being aidednot onlyby the agitative motion imparted to the table bymeans not ing across the'rifiles, while the non-floatable gangue particles and othernon-floatable .con

aeoaaos stitue'ntsof the ore are trapped along the feed side of therifiies and proceed to the rightrhand sidev of the table to launder 10,due to, the-force imparted to such'particles by the agitative moe tionof the table.- The instant process is. illustrated by placing pipes 'Ilwhich may be constructed of iron, steel, rubber, plastic, or, othersuitable materialabove and, across the surface orthe table andsubstantially parallel withxrespect to the riffles 3. .The pipes l I aresupported and supplied with water by? conduits l2,',andare perforated atsuitable'in'tervals so that a plurality of jets of water may beprojected into the particles present and collected along any. desiredlength of any particular rifile. Figures 2, and ,3 indicate-more clearlythe positioning of perforated pipes |2 with respect to the rifiles 2 and3, whereby jets of water-or other suitableaqueous media are directedinto the gangue particles which collect along the feed side of theriflies 3. While the drawings illustrate the position of said pipesabove the feed side of the rifiies 3 and parallel thereto, it is to beunderstood that the pipes maybe also placed above the feed side of anyone of a plurality of rifiies, either 2 or 3, providing-that at leastone riffie without jetsis positioned'between; rifiles equipped withjets. It is preferable to conduct the instant process by directing Waterjets along a riffie by meansgof a perforated pipe; but it is notintended that the invention be limited to any such particular device. Onthe contrary, water jets may be projected into the particles collectedalong any particular riflie or plurality of rifiiesby employing severallengths of pipe vertically positioned along the feed side of anyparticular riiile, thereby achieving substantially the same results.Alternatively, a pipe may be horizontally positioned along thefeed sideof one or moreriffles, said pipe .being provided with a continuous ordiscontinuous slot or orifice which faces the surface of the table.-Water may then be directed into the" gangue particles through saidslot, thereby. providing aplurality of streams of water'. which agitatethe particles present along the feed side of the rifiles and into whichsaid streams are directed.

In a preferred embodiment of the invention, a finelyv dividedphosphate-bearing material, which comprises the middlings fraction of aflotation table concentration of phosphate ore as obtained from aroughertable concentration of phosphate ore in accordance with conventionalprocedures which have been established in the phosphatev industry, andwhich. contains silica and phosphate values in the ratio of about 2'toabout 1 parts by weight of silica per part of phosphate, is conditionedin an aqueous pulp with a small amount of anionic or'negative-ion agentof the type, previously herein described. Preferably, a fraction of 1%of tall oil, or sodium soap thereof, and asmall amount of unsaponifi-vable oilfor examplea fraction of 1% of fuel oil-are employed. Thereagentized pulp is then admitted into thefeed box of anapparatussimilar to thatwhich is diagrammatically described in theaccompanying drawing. It is subsequently distributed over the upperedgeof the rifll'ed surface 'and'is permitted to flow across the rifiiedsurface in'a stream of water which entersthe table through .adistributor. As aresultof the concentrating "action ofv this table,augmented by the water jets which have bee'nfine corporated intothe'device byme'ans of four: or. five perforated'pipes' l l positionedalong riiiie's 8 3, a concentrate is collected in launder 9 whichcontains about 76% B. P, L. on a dry basis, achieving-a recovery ofabout, 90% of the phosphate values present in the feed to the table.This is in contrast with arecovery of about 30% which is achieved bysuch an operation in the absence ofwater jets applied to the riiiles ofatable concentratort. 1 In a further embodiment of, the invention, acomposition comprising sylvite and halite present in a ratio of betweenabout 1 and about 2 parts by weight of sylvite per part of'halite, andwhich has been obtained as a combination middlings and'tailingsfractionfrom a rougher table. concentration of sylvinite ore inaccordance With methods established in the potash industry, isconditioned in a brine which is saturated with respect to sylvite withreagent selected from the group consisting of aliphatic aminescontaining at least one alkyl group having 7 to 18 carbon atoms andtheir water-soluble acid addition salts. A particularly highconcentration of sylvite may be obtained by conditioning asylvite-halite composition containing said materials in the aforesaidratio by conditioning. the pulp with reagent consisting of the aceticacid addition salts of a mixture of the aliphatic amines comprisingabout 25% by weight of hexadecylamine and about by weight ofoctadecylamine. The resultant reagentized pulp is then fed to a tableconcentrating deviceof the type described in the accompanying drawing,which is equipped with brine jets, said brine being substantiallysaturated with respect to sylvite or sylvinite. A concentrate of sylviteor potassium chloride is collected in the launder 9, while the halite orsodium chloride values are collected in launder [B and discarded. Animprovement in the over-all recovery of sylvite from sylvinite ore isobtained which approximates that achieved in the concentration ofphosphate values as illustrated by the process describedinthe'precedin'g paragraph. i

In still a further embodiment of the invention, halite may beconcentrated from sylvinite ore, or from compositions containing sylviteand haliteg-by'pre paring an aqueous. pulp of the materialto beconcentrated by admixing the same with an aqueous solution which issubstantially saturated with respect to halite, and reagentizing theresultant pulp with negative-ion agent having an affinity for haliteparticles. Prefer.- ably, a small amount of composition, comprise ingagent selected from the group consisting of fatty acids having 7 to 18carbon atoms, tall oil, rosin, and alkali metal soaps of .said agentsmay be employed in order to .properly condition the pulp. Thereagentized mixture is then flowed across a device of the typeillustrated in the accompanying drawing in a direction transverse withrespect to themovement of the agitative motion of the riiiied table.Brine jets are directed through fourorfive pipes ll positioned along'therifiles 3 of the .table into the sylvite particles which are presentalong the feed side of the riiiles, said brine being substantiallysaturated with respect to halite. This, achieves an over-all recovery'of halite from compositions containing'the same in association withsylvite to-a degree which: has heretofore been-impos sible to achieve.

In order to more fully illustrate the natu eand character of theinvention, but-with no in-' tention of being: limited thereby,,;thefollowing example is recited-:. 1 1

,Emm

Aphosphatic rock typical oi thetype: found in the Floridaphosphate areawas preliminarily classifiedtoa meshsize of -.1' mm. to +35 mesh. Thisfraction of the rock was then reagentized in an aqueous pulp with about1.5 lbs. of tall oil, about 2 lbs. of fuel oil, and about 0.5 lb. ofherosene. A sufiicient amount of an aqueous. solution of caustic sodawas added thereto in. order to produce a final mixture having a pHbetween about 8.5- and 9.0. The resultant pulp was then subjected to. arougher concentration for the recovery of the phosphate valuesvcontained in therock by flowing the same over a .D'eisterOverstromdiagonal table of the type described in the Taggart publicationpreviously mentioned herein and as illustrated diagrammatically in theaccompanying drawing. No water jets-were used in this particularoperation. The rougher table concentration produces threefractions: that-is, a concentrate containing about 75% B. P. L., a small tonnagemiddling fraction which, is circulated back to the feed, and a ton nageof rougher tails which is. about 20% of the original feed. These roughertails contain about 25-35% B. P. L. They are. then subjected to asecond'tabling, after re-reagentizing with a small amount of tall oil,fuel oil, and kerosene, plus enough caustic to give the pulp a finalpI-I of about 8.5-9.

The concentrate which is obtained by the tabling of the rougher tailscontains about 75- 80%. B. P. L. and about 2-5% insoluble on a drybasis. The tails from this operation analyzed about 25% B. P. L. withabout 68% insoluble. The percent recovery of the phosphate'valuescontained in the feed or rougher tails fraction is about 32%. I

During the table concentration of the rougher tails fraction. asdescribed above, the concentrating action of the table was augmented bydirecting water jets into the particles which collect along the feedside of the riffies. Thiswas accomplished by placing perforated pipesalong the feed side of four or five of the large riflies 3 andsubstantially parallel thereto, and forcing water through theperforations into the silica particles. As a result, theconcentratecontaining the phosphate values has a B. P. L. content ofbetween about '75 and 77%, and an insoluble content of between about 6and about-8%, on adry basis.- The tailings-from this operation have aB'. P. L. content of only about and an insolublecontent of about 93%.The recovery of the phosphate values contained in the feed to' to onlyabout one-fifth of that present in tailings obtained in the absence ofthe water jet operation. Not only is an improvement in percent achieved,but it is possible to greatly increase the rate of feed to the table,thereby increasing the concentrating capacity of same. The smallincrease in the percent insolubles present in the concentrate whenemploying water jets in accordance with the instant process is notdeleterious and is amply compensated by the im- 10' proved recoveries.of the phosphate values contained in the feed.

While the above example illustrates the con centrationof the phosphatevalues present in a particular phosphatic-siliceous composition, it isto be understood that other minerals of the type previously hereindescribed may also be advantageously concentrated, attendant withimproved recoveries by employing suitable extensions and modificationsof the process as above illustrated. It is known that certain reagentsare more specific for particular mineral values contained incthe-Various ores which have been mentioned herein; and that the choice ofreagents, rate of fiow of, the flotation feed across the rifiledconcentrating surface, the angle of inclination of said surface duringthe concentration,and.-the degree of agitation will be dependent uponthe particular mineral or mineral-containing composition which is soughtto be concentrated. I

While the example recited herein illustrates the use of aDeister-O-verstrom diagonal deck concentrati ng table, it is to beunderstood that other types of .riflled concentrating surfaces may beemployed which may or may'not be subjected to agitative motion. Forexample, the table. devices devised by Rettinger, Wilfiey, and others,as illustrated in the aforementioned Taggart publication, may also beemployed; the choice of any particular device depending upon the mineralto be concentrated from a specificore.

It .is not intended to limit the instant. process to the particularprocedural" details described herein; but any extensions and/ ormodifications which are equivalent thereto are deemed to be within, thescope of the invention.

Having thus fully described the nature and character of the invention,what is desired to be secured by Letters Patent is: I

1. In a process for concentrating non-metallic minerals from orecontaining the same in association with gangue particles by flowingareagentized' pulp of said ore in an aqueous stream over a. riffledsurface; the improvement, comprising directingan aqueous stream from apoint above the table into the particles present along and collected atthe feed, side of the rifiies, at least one rifiie with said streampreceding at least one rifile without said stream with respect to thedirection of flow of said pulp, and collecting a concentrate of saidminerals.

2. In a process for concentrating non-metallic minerals from orecontaining the same in association with gangue particles by flowing areagentized pulp of said ore in an aqueous stream over a rifiledsurface; the improvement comprising directing a plurality of aqueousjets into the particles present along and collected at the feed side ofthe rifiies, said jets being so positioned that at least one rifilewithout jets is situated between riflies with jets, and collecting aconcentrate of said minerals.

3. In a process for concentrating non-metallic mineralsfrom orecontaining the same in asso ciation with gangue particles by flowing areagentized pulp of said ore in an aqueous stream over a rifiled,inclined surface; the improvement comprising directing a plurality ofaqueous jets from a point above the table into the particles presentalong and collected at the feed side of the rifiles, said jets being sopositioned that at least one rifile without jets is situated betweenrifiies with jets, and collecting a concentrate-of said minerals.

1 :4. In a process for concentrating non-metallic minerals from orecontaining thefsan'i'einassociation with gangu'e particles by flowing'areagentized' pulp'of saidore in an aqueous'stream over a riffled,inclined, moving surface; the improvement comprising directing 'aplurality of aqueous jetsinto the particles present along and collectedat the feed side of the riflles, said jets being so positioned that atleast one riflle without jetsis situated between riflles with jets, andcollecting a concentrate of 'said'minerals. a

5.111 a process for concentrating phosphate values from a phosphatic'ore containing the same in association'with silica by flowing an aqueousreagentize'dpulp of saidore in'a stream of water over ar'ififledfinclined, moving surface; the improvement comprising directinga plurality of water jets into the particles'ipresent along andcollected at the feed side of the riflies, said jets being so positionedthat at least one riiile without jets is situated between riffies withjets, and collecting a concentrate of phosphate values.

6. In a process for concentrating phosphate values from a phosphatic orecontaining the same in association with silica by flowing an aqueousreagentized pulp of said ore in a stream of water over a rifiled,inclined, moving surface; the improvement comprising directing a streamof water from a point above the table into the particles present alongand collected at the feed side of the riffles, at least one rifile withsaid stream precedingatleast one riflie without said stream with respectto the direction of flow of said pulp, and collecting a concentrate ofphos-.

phatevalues.

'7. In a process for concentrating phosphate the movement of saidsurface; directing a plurality of water jets from a point above thetable into the particles present along and collected at the feed'side ofthe rifiles, said jets being placed at alternate -riflies andsubstantially parallel there to; and collecting a' concentrate ofphosphate values.

10. A process for concentrating finely divided phosphate-bearingmaterial containing silica and phosphate values in a'ratio of about twoto about one parts by weight, which comprises preparing an aqueous pulof said phosphate-bearing ma-' values from a .phosphatic ore. containingthe same in association with silica by flowing an aqueous pulp of saidore which contains neg,- ative-ion agent having an afiinity forphosphate values in a stream of water over a riflled, inc1in'ed,' movingsurface; the improvement comprising directing a plurality of water jetsfrom a point above the table into the particles present along andcollected at the feed side of the riffies, saidjets being placed atalternate rifiies and substantially parallel thereto, and collecting aconcentrat'e' of phosphate values.

8.'A ,process for concentrating finely divided phosphate-bearingmaterial containing a major amount of silica and a minor amount ofphosphate, values, which comprises reagentizing an aqueous pulp of saidphosphate-bearing material with negative-ion agent having an affinityfor phosphate values; flowing the reagentized pulp in a stream of waterover a riflled, inclined, moving surface in a direction transverse withrespect to the movement of said surface; directing a plurality of Waterjets from a point above the table into the particles present along andcollected at the feed side of the rifiles, said jets being placed atalternate rifiies and substantially parallel thereto; and collecting aconcentrate of phosphate'values.v

9. A process for concentrating finely divided phosphate-bearing materialcontainin silica and phosphate values in a ratio of about two to aboutone parts by weight, which comprises preparing an aqeuou's pulp of thesaid phosphatebearing material; reagentizing said pulp with a smallamount of tall oil soap and a small amount of unsaponifiable oil toselectively float the phosphate values; flowing the reagentized pulp ina stream of water over a rillled, inclined, moving surface in adirection transverse with respect to terial; adding thereto a fractionof 1% of sodium soap of tall oil, a fraction of 1 of fuel oil, and afraction of 1% kerosene; flowing the reagentized pulp in a stream ofwater over a riflied, inclined, moving surface ina direction transversewith respect to the movement of said surface; directing a plurality ofWaterjets into the particles present along and collected at the feedside of the rifiles, said jets being placedat alternate riflles andsubstantially parallel thereto; and collecting a concentrate ofphosphate values. V 11. In a process for concentrating sylvite fromsylvinite ore by flowing an aqueous reagentized pulp of said ore in astream of brine over a rifiled, inclined, moving surface; theimprovement comprising directing a plurality of brine jets into theparticles not floated and which are present along and collected at thefeed side of the rifiles, said jets being so positioned that at leastone riflle without jets is situated vbetween riflles with jets and saidbrine being substantially saturated with respect to sylvite, andcollecting a concentrateof sylvite. 1

'12. In a process forconcentrating sylvite from sylvinite ore by flowingan aqueous reagentize'd pulp of said ore in a stream of brineover. arifllecl, inclined, moving surface; the improvement comprising directinga stream of brine into the particles not floated and which are presentalong and collected at the feed side of the rifiles, at least one rifllewith .saidstream preceding at least oneriflle Without said stream withrespect to the direction of flow of said pulp and said brine beingsubstantially saturated with respect to sylvite, and collecting aconcentrate of sylvite.

13. In a process for concentrating sylvite from sylvinite ore by flowingan aqueous pulp com- 7 prising finely divided sylvinite ore, said orebeing reagentized with a positive-ion agent having an affinity forsylvite, in a stream of brine over a riflied, inclined, moving surface;the improvement comprising directing a plurality of brine jets into theparticles present along and collected at the feed side of the rifiies;said jets being placed at alternate rifiies and substantially parallelthereto and said brine being substantially saturated with respect tosylvite, and collecting a concentrate of sylvite.

14. A process for concentrating sylvite from a composition comprisingsylvite and halite in a ratio of about one to about twoparts by weight,Which comprises preparing an aqueous pulp of said composition;conditioning the pulp with reagent selected from the group consisting ofaliphatic amines containing at least one. alkyl group having 7-18 carbonatoms and their watersoluble acid addition salts; flowing thereagentized pulp in a direction transverse with respect to the movementof said surface; directing a plurality of brine jets into the particlespresent along and collected at the feed side of the riflles, said jetsbeing placed at alternate rifiies and substantially parallel thereto andsaid brine being saturated with respect to sylvite; and collecting aconcentrate of sylvite.

15. A process for concentrating a composition comprising sylvite andhalite in a ratio of about one to about two parts by weight, whichcomprises preparing an aqueous pulp of said composition in a saturatedsolution of same; conditioning the pulp with reagent consisting of theacetic acid addition salts of a mixture of aliphatic amines comprisingabout 25% by weight of hexadecylamine and about 75% by weight ofoctadecylamine; flowing the reagentized pulp in a stream of brine over ariffied, inclined, moving surface in a direction transverse with respectto the movement of said surface; directing a plurality of brine jetsinto the particles present along and collected at the feed side of therifiies, said jets being placed at alternate riffles and substantiallyparallel thereto and said brine being saturated with respect to sylvite;and collecting a concentrate of sylvite.

16. A process for concentrating a composition comprising sylvite andhalite, which comprises preparing an aqueous pulp of said composition ina solution substantially saturated with respect thereto; reagentizingsaid pulp with negative-ion agent having an affinity for haliteparticles; flowing the reagentized pulp in a stream of brine over arifiled, inclined, moving surface in a direction transverse with respectto the movement of said surface; directing a plurality of brine jetsinto the particles present along and collected at the feed side of therifles, said jets being so positioned that at least one riflie withoutjets is situated between riflles with jets and said brine beingsubstantially saturated with respect to halite; and collecting aconcentrate of halite.

17. A process for concentrating sylvinite ore, comprising preparing anaqueous pulp of said ore in a solution substantially saturated withrespect thereto; reagentizing said pulp with a composition comprising analkali metal soap of an agent selected from the group consisting offatty acids having 7-18 carbon atoms, tall oil, rosin, and alkali metalsoaps of said agents; flowing the reagentized pulp in a stream of brineover a riflied, inclined, moving surface in a direction transverse withrespect to the movement of said surface; directing a plurality of brinejets into the particles present along and collected at the feed side ofthe rifiles, said jets being placed at alternate riffles andsubstantially parallel thereto and said brine being saturated withrespect to halite; and collecting a concentrate of halite.

IRA M. LE BARON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 30 Number Name Date 1,520,451 Sperry Dec. 23, 19241,956,296 Martin Apr. 24, 1934 1,968,008 Chapman July 24, 1934 2,287,115McCluskey June 23, 1942

